Method of coating metals.



' 110,7 1,230. PATENTED JAN.- 31, 1905. V

' .'H. RODMAN.

METHOD OF COATING METALS;

AIfPLIQATION IILED DBO. 3 1904.

' UNITED STATES Patented January 31, 1905.

PATENT OFFICE.

HUGH. RODMAN, or CLEVELAND, OHIO.

SPECIFICATION forming part of Letters Patent No. 781,230, dated J anuary31, 1905.

Application filed December 3, 1904. Serial No. 235,324;-

To all whom it may concern: 7

Be it kn own that I, HUGH RoDMAN, a citizen of the United States,residing at Cleveland, in

the county of Cuyahoga and State of Ohio, have invented certain new anduseful Improvements in Methods of Coating Metals, of which the fol?lowing is 'a specification.

Thisinvention is a method of securing upon a metal, as iron orcopper,'an adherent coating of-a fusible metal, as lead, tin, or Zinc.

' According to myinvention the coating is effected in a bath of thefusible metal in which is maintained during the coating operation asuitable proportion of a highly-electropositive metal, such as potassiumor sodium. Preferably the metal to be coatedis preliminarily subjectedto the action of such electropositive metal and is thereby cleanedand'prepared' for the reception of the adherent coating,

For a full understanding of my invention reference is made to theaccompanyingdrawings, wherein Figure 1 isa vertical section of anarrange,

ment of apparatus for carrying out my method. Figs. 2 and 3 are similarviews of modified arrangements.

Referring to Fig. 1. 1 is a cast-iron vessel for containing the fusiblemetal 2 and a supernatent body 3,which may consist of the moltenhydroxid of an alkali metal. 4 is an anode dip ping into the moltenhydroxid into proximity to the surface of the fusible metal 2. For usein a bath of hydroXid the anode may conveniently be of iron. 5represents a wire-0f iron, copper, or other metal .to be coated,

which is directed by suitably-placed rollers or guides 6 6 through themolten hydrorrid and the body of fusible metal underlying it, the wirebeing moved through the bath by any desired means.

nection.

According to the above arrangement the cathode comprises the pot 1 andthe molten metal 2 and wire 5, which are in metallic connectiontherewith. The electropositive element, as potassium or sodium, willtherefore be deposited both upon the surface of the fusible metal 2 andupon the wire 5. The alkali metal rapidly diffuses through and dis- 7indicates the cathode consolves in the fusible metal, such diffusion andsolution being aided bythe stirring action of the moving wire and servesto secure a closelyadherent and uniform deposit of the coating metal.That portion of the alkali metal which is deposited upon the wire 5eflectively cleans it by the reduction of any coating of oXid,

thereby avoiding the necessity for any extensive preliminary pickling orcleaning. I may increase the'path of travel of the wire through theelectrolyte to an extent sufficient to insure a thorough cleansing.

According to the arrangement illustrated in Fig. 2 a partition 8 dependsinto the fusible metal 2, dividing the pot into two compartments,sealed. by the fusible metal. One of these compartmentscontains theanode and electrolyte and the other the guides 6 6 for the wire. Thisarrangement is less desirable, however, than that shown in Fig.1 or Fig.8, be-

cause themetal to-be coated is not preliminarily cleanedby the cathodereaction.

Fig. 8 illustrates a similar compartmental cell having the guides 6 6 soplaced that the wire is carried to the molten bath through theelectrolyte, but is withdrawn from the molten bath at a point where thelatter is not covered by the electrolyte. This arrangement isadvantageous for the reason that no alkali metal is electrodeposited onthe Wire after the application of the coating. The apparatus may beotherwise modified without departing from my invention.

I do not limit myself to the treatment of wire, which is described byway of illustration only, butmay coat metal in any desired form, nor'doI limit myself to a continuous process, it being essential merelythat a due proportion of the electropositive metalbe maintained in thebath throughout the coating operation. If desired, I may deposit thealkali metal upon the wire only, some alkali metal being transferred bythe movement of the wire to the molten coating metal and securing anadherent coating thereof.

I claim-- consists in subjecting it tothe action of a molten coatingmetal, and malntaining in said 1. The method of coating a metal which Icoating metal a suitable proportion of an alkali metal, substantially asdescribed.

2. The method of coating a metal which consists in cleaning it by theaction of an alkali metal, and thereafter coating it in a molten bath,substantially as described.

3. The method of coating a metal which consists in cleaning it by theaction of an alkali metal, and thereafter coating it in a molten bathcontaining an alkali metal, substantially as described.

4. The method of coating a metal which consists in maintaining in amolten body of the coating metal a suitable proportion of an alkalimetal, and subjecting the metal to be coated to the action of said body,substantially as described.

5. The method of coating a metal which consists in maintaining in amolten body of the 20 coating'metal a suitable proportion of an alkalimetal, and moving the metal to be coated through said body,substantially as described.

6. The method of coating a metalwhieh consists in electrodepositing analkali metal on the metal to be coated, and thereafter subjecting saidmetal to the action of a coating metal, substantially as described.

7. The method of coating a metal which consists in electrodepositing analkali metal on the metal to be coated, and thereafter subjecting saidmetal to the action of a coating metal and an alkali metal,substantially as described.

In testimony whereof I afiix my signature in presence of two witnesses.

HUG-H RODMAN.

itnesses:

THEODORE A. \VILLARI), R. G. Sm'rir.

